1. Field of the Invention
This invention relates to apparatus, methods and media for video data recording and reproduction.
2. Description of the Prior Art
In many video data recording systems, video data (possibly after a stage of data compression) is recorded onto successive obliquely scanned parallel tacks on a recording tape medium.
If the data is recorded onto the tape tracks in the same order in which the data appears in the original picture, then a tape error such as a scratch or a dropout can lead to the loss of many adjacent pixels forming a contiguous area of the image. The fact that such a contiguous area has been lost makes it very difficult to use error concealment techniques which rely on interpolating missing pixel values from temporally or spatially surrounding (correct) pixel values.
In order to address this problem, so-called data shuffling has been proposed, whereby adjacent sections of data on a tape track represent non-adjacent areas in the image. So, if a tape error causes the loss of a number of such adjacent track sections, the shuffling arrangement translates this into a loss of several widely-spaced image areas which are surrounded by error-free pixels. In this way, data concealment can still be used.
It is an object of the invention to provide an improved data shuffling technique to provide increased immunity against data errors on tape replay.